Vending machines delivering cups containing freshly made beverages are known whereby the feeding of the various ingredients such as powder for the preparation of soda or coffee as well as sugar is controlled with respect to amount by adjusting the individual dispensing devices and the water feeding device in such a manner that associated delivery mechanisms are activated upon the adjustment for a constant period of time each time the vending machine is activated for preparing and dispensing a beverage. These These known vending machines do not disclose completely satisfactory results with respect to the composition of the beverage as the amounts dispensed have a tendency to vary to a sometimes unagreeable extent in spite of the adjustment. Consequently a demand exists for a vending machine capable of currently to carry out an adjustment of the dispensed amounts of powder and optionally also water.